Nursing Elites

1. Which of the following best describes a group of cells working together?

• A. Organelle
• B. Tissue
• C. Organ
• D. Organ system

Correct answer: B

Rationale: The correct answer is B: Tissue. Tissue is a group of cells that work together to perform a specific function. Organelle refers to specialized structures within a cell, organ is a structure made up of different types of tissues working together, and organ system is a group of organs working together to perform complex functions. Therefore, tissue is the most appropriate term to describe a group of cells working together.

2. A light ray travels from air (refractive index 1.00) into water (refractive index 1.33). What happens to its speed and direction?

• A. Speed increases, direction bends towards the normal.
• B. Speed increases, direction bends away from the normal.
• C. Speed decreases, direction bends towards the normal.
• D. Speed and direction remain unchanged.

Correct answer: C

Rationale: When a light ray travels from air (lower refractive index) to water (higher refractive index), its speed decreases due to the change in the medium. This is because light travels slower in denser mediums. As the light ray enters the denser medium, water in this case, it bends towards the normal (the line perpendicular to the surface of the water). This phenomenon is known as refraction. Choice A is incorrect as the speed of light decreases when entering a denser medium. Choice B is incorrect as the direction bends towards the normal, not away from it. Choice D is incorrect as the speed and direction of the light ray do change when moving from air to water.

3. Which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow?

• A. Skeletal muscle
• B. Smooth muscle
• C. Cardiac muscle
• D. Striated muscle

Correct answer: B

Rationale: Smooth muscle is the correct answer. It is found in the walls of blood vessels and helps regulate blood flow by contracting and relaxing to adjust the diameter of the vessels. Skeletal muscle, found attached to bones, is responsible for voluntary movements and is not typically found in blood vessel walls. Cardiac muscle is specific to the heart and responsible for pumping blood, not found in blood vessel walls. Striated muscle, another term for skeletal muscle, is characterized by its striped appearance under a microscope but is not present in blood vessel walls.

4. In the K-capture process, a type of electron capture, from which electron shell does the electron get captured?

• A. The outermost s-orbital
• B. An inner p-orbital
• C. An inner d-orbital
• D. Any available electron shell

Correct answer: B

Rationale: The K-capture process involves the capture of an electron from the innermost electron shell, known as the K-shell. The K-shell comprises s and p orbitals. During the K-capture process, an electron is specifically captured from an inner p-orbital within the K-shell. Choices A, C, and D are incorrect because K-capture involves capturing an electron from the innermost shell (K-shell) which consists of s and p orbitals, not the outermost s-orbital, inner d-orbital, or any available electron shell.

5. Melanin, the pigment responsible for skin color, is produced by

• A. Keratinocytes (These cells produce keratin)
• B. Melanocytes
• C. Sebocytes (These cells produce sebum)
• D. Langerhans cells (These cells are part of the immune system)

Correct answer: B

Rationale: Melanocytes are the cells responsible for producing melanin, the pigment that determines skin color. Melanin gives skin its color and protects it from the harmful effects of UV radiation. Keratinocytes produce keratin, a tough protein that forms the outer layer of the skin, hair, and nails. Sebocytes produce sebum, an oily substance that helps moisturize and protect the skin. Langerhans cells are a type of immune cell found in the skin that play a role in protecting against infections and foreign substances but do not produce melanin.

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